In the manufacture of microelectronic devices, such as processors, controllers, and memory, the desired structures are formed on a wafer. Individual dies are cut from the wafer and then sealed into a package. The package has an array of pins, pads, or lands that make contact with the rest of the device, typically through a socket or a printed circuit board to allow the die to be operated while within the package. Before packaging, each die is tested to ensure that it has been manufactured and operates as intended. The dies may be tested while still part of the wafer or after dicing or both. After packaging, each package is tested to ensure that it has been manufactured correctly and operates as intended.
To perform the tests, a die which may or may not be packaged is placed on or attached to a thermal test head which controls the temperature of the die. The test head will have heaters and may also have cooling so that the die may be tested under extreme environmental circumstances. The die may also be heated to simulate a very high processing or operational load. The high and low heat not only stress the die but also stress the thermal test head. The stress comes not only from the extreme temperatures but from changing from a high to a low temperature.
High speed, controllable, and accurate test technologies provide greater reliability in the end product, higher factory throughput, and reduced manufacturing cost. High performance heating and cooling stages may be used for many different test processes. In addition, such stages may be used for manufacturing processes such as chip attach and thermal compression bonding.